Laser materials processing as known in the art and used herein refers to performance of materials processes, such as cutting, welding, drilling, heat treating and soldering, using a laser beam. Typically, the average power of such a laser beam may range from as little as less than one watt to thousands of watts, the specific power being selected on the basis of the particular process being performed. Laser beam power required for materials processing generally is much greater than laser beam power required for other laser based systems such as communication systems.
Before now, in spite of advances in laser technology, performing operations on composite objects such as cutting had to be performed manually using mechanical tools such as razor blades. The term composite object, as used herein, refers to an object typically composed of combinations of materials such as metal alloys and/or plastics, usually with the addition of strengthening agents. The term composite object element, as used herein, refers to a section of the composite object formed by performing a laser cutting operation on the composite object. For example, a composite object may be cut in halves by a laser beam to form two composite object elements. One type of composite object is a layered composite object wherein each layer has respective optical, mechanical and thermal properties. These variations in properties between the layers, until now, prevented laser materials processing of layered composite objects to provide composite object elements.
For example, when attempting to perform a laser materials processing operation on a layered composite object, a beam power level sufficient to process one layer may not be sufficient to process another layer. Increasing the beam power level, however, may result in damaging the first layer. Damaging a layer of a layered composite object is undesirable because such damage typically requires that the composite object be discarded. This, of course, leads to waste and increased costs.
In performing laser materials processing, it is known to use a neodymium:Yttrium-Aluminum Garnet (Nd:YAG) laser operating in a pulsed mode. An Nd:YAG laser is a source of 1.06 micrometer wavelength energy. It is also known to transmit a beam from a laser through an optical fiber to an output coupler. Further, it is known to alter the frequency/wavelength of a beam from a laser. Until now, however, there is no known control system for controlling laser materials processing of composite objects.
When controlling laser processing of composite objects, it is preferred that such control be automated so that advantages of using a laser based system are not lost. Specifically, one advantage of utilizing laser materials processing systems is a reduction in processing time. If a control systems results in substantially increasing the time period required to complete processing, the time saving advantage of using a laser system may be lost.
It is therefore an object of the present invention to provide a laser materials processing system for processing composite objects.